1. Field of the Invention
The present invention generally relates to a pixel structure and the fabrication method thereof, and more particular, to a multi-domain vertical alignment pixel structure (MVA pixel structure) and the fabrication method thereof.
2. Description of Related Art
The rapid development in the multimedia industry is largely attributed to the progress in the semiconductor devices and display apparatuses. In terms of displays, the liquid crystal displays (LCDs), with such advantages as high display quality, high space utilization, low power consumption and no radiation, have played a major role in the mainstream display market. In order to improve the LCD display quality, various LCDs with wide viewing angle have been developed and are available on the market today. The common LCDs with wide viewing angle are, for example, in-plane switching (IPS) LCDs, fringe field switching (FFS) LCDs and multi-domain vertical alignment (MVA) LCDs.
FIG. 1A is a diagram of a conventional multi-domain vertical alignment pixel structure. Referring to FIG. 1A, an MVA pixel structure 100 is disposed on a substrate 102. The MVA pixel structure 100 comprises an active device 110, a first pixel electrode 120, a second pixel electrode 122, a plurality of capacitor-coupling electrodes 130 and a common line 140. Specifically, the active device 110 is electrically connected to a scan line 104 and a data line 106. In addition, the active device 110 is electrically connected to the first pixel electrode 120 through a via hole C1. The scan line 104 delivers a scanning signal for turning on the active device 110, followed by delivering a display signal to the first pixel electrode 120 through the turned-on active device 110. On the other hand, the active device 110 is electrically connected to the capacitor-coupling electrode 130, while the common line 140 is electrically connected to a reference voltage.
As supposed to be, the first pixel electrode 120 is insulated from the second pixel electrode 122, and the second pixel electrode 122 is electrically coupled to the capacitor-coupling electrode 130 therebelow. In other words, once the active device 110 is turned on, the first pixel electrode 120 and the second pixel electrode 122 respectively take different voltages, so that the liquid crystal molecules (not shown) respectively corresponding to the first pixel electrode 120 and the second pixel electrode 122 have different orientations.
However, an ITO residue issue may occur during the process of the MVA pixel structure 100 so that the first pixel electrode 120 is electrically connected to the second pixel electrode 122. As shown by FIG. 1B, which is the sectional view along sectioning plane I-I′ in FIG. 1A, the residue R, remained during fabricating the first pixel electrode 120 and the second pixel electrode 122 and caused by the particles of environment or machine, may be located between the first pixel electrode 120 and the second pixel electrode 122. The residue R makes the first pixel electrode 120 and second pixel electrode 122 electrically connected to each other, which further leads to a poor display performance of the MVA pixel structure 100, and the problem needs to be solved properly.